Capabilities of Hydrogen as a Supplementary Fuel for Compression Ignition Engines - A Review

Mihail Peychev

dual-fuel operation, hydrogen, hydrogen-diesel engine, hydrogen in internal combustion engines

The current article describes the process of conversion of a compression ignition (diesel) engine to dual-fuel engine, operating with diesel fuel and hydrogen simultaneously. Properties of hydrogen – physical and chemical and the qualities of hydrogen as fuel are analyzed. Different methods for hydrogen storage – physical, chemical and adsorption are described. Special attention is paid to precautions when operating with hydrogen and the elements needed to use during engine conversion, in order to ensure safe hydrogen-diesel operation. Two hydrogen injection options are possible – hydrogen direction injection and port injection at engine intake. Both are explained. A short analysis of approximate conversion costs for dual-fuel operation is made. Hydrogen gas price is also noticed. The final part of the article does a brief review on the research of several authors about hydrogen-diesel dual fuel operation in compression ignition engines. Results from these authors research, considering engine performance, economy and emissions, as well as combustion process parameters, are cited. As these studies define a coefficient used to determine hydrogen share in total fuel (diesel fuel plus hydrogen) the current article analyses the influence of changing hydrogen share in fuel on engine operation. Authors different experiments are taken into account in order to assess the influence of growing hydrogen content in fuel on engine economy and emissions, including total and specific fuel consumption, thermal efficiency, exhaust gas opacity, nitrogen oxides concentration etc. As authors have controversial opinions in some cases influence of hydrogen is considered positive or negative depending on how much authors claim positive and how much claim negative influence. Results from the review concerning effects of hydrogen on diesel engine operation are summarized in a table for easier perception.

https://dx.doi.org/10.31873/IJEAS.7.12.10